(4) Internet access and e-mail: Digital TV STB can realize Internet access function through the built-in cable modem. Users can access the Internet via a set-top box browser, send e-mail, and provide a variety of interfaces to connect to PCs, using PCs.

(5) Software online upgrade: Can be regarded as one of the applications of data broadcasting. The data broadcast server transmits the upgraded software to the set-top box, which recognizes the version number of the software, receives the software at the same time, and updates the software stored in the storage.

(6) Conditional reception: The core of conditional reception is scrambling and encryption, digital TV set-top box should have the function of scrambling and decryption.

With the development of digital TV and network technology, the function of digital TV set-top box will be perfected, especially the development of single chip PC technology, will impel the digital TV set-top box to integrate each part of hardware highly in physical structure, form STB core chip, reduce volume, lower cost and improve performance. The external interface will be more rich, through the USB interface can be connected with digital cameras, through the IDE interface can be linked to the hard drive to achieve program storage. Interactive set-top box will become the mainstream of digital TV set-top boxes, users in analog color TV can not only watch digital TV, but also to achieve entertainment and Internet access.